feat: MD pipeline — market-data-service hardening + SenpAI NATS consumer

Producer (market-data-service):
- Backpressure: smart drop policy (heartbeats→quotes→trades preserved)
- Heartbeat monitor: synthetic HeartbeatEvent on provider silence
- Graceful shutdown: WS→bus→storage→DB engine cleanup sequence
- Bybit V5 public WS provider (backup for Binance, no API key needed)
- FailoverManager: health-based provider switching with recovery
- NATS output adapter: md.events.{type}.{symbol} for SenpAI
- /bus-stats endpoint for backpressure monitoring
- Dockerfile + docker-compose.node1.yml integration
- 36 tests (parsing + bus + failover), requirements.lock

Consumer (senpai-md-consumer):
- NATSConsumer: subscribe md.events.>, queue group senpai-md, backpressure
- State store: LatestState + RollingWindow (deque, 60s)
- Feature engine: 11 features (mid, spread, VWAP, return, vol, latency)
- Rule-based signals: long/short on return+volume+spread conditions
- Publisher: rate-limited features + signals + alerts to NATS
- HTTP API: /health, /metrics, /state/latest, /features/latest, /stats
- 10 Prometheus metrics
- Dockerfile + docker-compose.senpai.yml
- 41 tests (parsing + state + features + rate-limit), requirements.lock

CI: ruff + pytest + smoke import for both services
Tests: 77 total passed, lint clean
Co-authored-by: Cursor <cursoragent@cursor.com>

services/senpai-md-consumer/docker-compose.senpai.yml

@@ -0,0 +1,40 @@
+# SenpAI Market-Data Consumer + NATS
+# Usage: docker-compose -f docker-compose.senpai.yml up -d
+version: "3.8"
+
+services:
+  nats:
+    image: nats:2.10-alpine
+    container_name: senpai-nats
+    ports:
+      - "4222:4222"
+      - "8222:8222"  # monitoring
+    command: ["--js", "-m", "8222"]
+    restart: unless-stopped
+
+  senpai-md-consumer:
+    container_name: senpai-md-consumer
+    build:
+      context: .
+      dockerfile: Dockerfile
+    environment:
+      - NATS_URL=nats://nats:4222
+      - NATS_SUBJECT=md.events.>
+      - NATS_QUEUE_GROUP=senpai-md
+      - FEATURES_ENABLED=true
+      - FEATURES_PUB_RATE_HZ=10
+      - LOG_LEVEL=INFO
+      - HTTP_PORT=8892
+    ports:
+      - "8892:8892"
+    depends_on:
+      - nats
+    restart: unless-stopped
+    healthcheck:
+      test:
+        - CMD-SHELL
+        - python -c "import urllib.request; urllib.request.urlopen('http://localhost:8892/health')"
+      interval: 15s
+      timeout: 5s
+      retries: 3
+      start_period: 10s